1. Field of the Invention
The present invention relates to an optical head device having a structure such that an actuator is mounted in a housing, and more particularly to an optical head device featuring improved accuracy of the positioning of the movable component of the actuator during assembly work.
2. Description of the Prior Art
Optical head devices for optically reading or writing signals to or from a disk have hitherto been structured such that an actuator for driving an objective lens is mounted in a housing, which incorporates a semiconductor laser as a light-emitting element and a photodetector as a light-receiving element. In the housing, there are formed an optical path for guiding a laser beam emitted from the semiconductor laser to the objective lens and another optical path for guiding the laser beam back to the objective lens after it is reflected by the disk.
When mounting the actuator to the housing, it has been necessary to perform skew adjustment of the actuator in both tangential and radial directions of the disk in order to adjust the optical axis of a laser beam incident on the disk so as to suppress coma aberration of the light spot focused on the disk.
In an optical head device such as this, as shown in Japanese Patent Laid-Open Publication No. 2000-48374, for example, the actuator is made capable of skew adjustment by designing it to be mounted to the housing in a manner to permit skew adjustment in both tangential and radial directions of the disk.
However, to perform the skew adjustment described above, it is necessary to carry out a manufacturing process using a special-purpose assembly jig and a complicated inspection process. This negatively effects production efficiency of the optical head devices and impedes attempts at cost reduction.
The structure of an optical head device formed capable of skew adjustment is itself an obstacle to decreasing the number of parts, and a problem remains that skew adjustment tends to slip back to some extent due to environmental changes, such as temperature and humidity.
Another problem with conventional art is that support positions of the ends the suspension wires, in other words, the actuator movable part side and the opposite housing side of each suspension wire, tend to vary, such that imbalance arises among the positions at which the suspension wires are strung. As a result, the position of the objective lens changes when the objective lens is shifted for tracking or focusing and optical performance is impaired.